Metal seal

Abstract

A metal seal of a non-circular ring which shows uniform sealing ability on whole periphery. The whole configuration of the metal seal is a non-circular ring having an R-shaped curved portion and a straight portion, and a cross-sectional configuration of the metal seal is changed as to make cantilever flexural rigidity larger on the straight portion than on the R-shaped curved portion.

What is claimed is: 
     
       1. A metal seal provided with a base portion, and a pair of cantilever elastic leg pieces protruding from the base portion as to be parallel or opening toward forth ends, each of which has a small convex portion for sealing on the forth end to contact each of facing two flat faces, comprising a construction in which an entire configuration is a non-circular ring having an R-shaped curved portion and a straight side portion, at least one of a protruding dimension, a thickness dimension, and a thickness of leg piece base portion of the cantilever elastic leg piece is made different on a first center position of the R-shaped curved portion and on second center position of the straight side portion, and cantilever flexural rigidity of the cantilever elastic leg piece is set larger on the second center position than on the first center position when compared only by cross-sectional configurations, a cantilever flexural rigidity of the metal seal being ununiform for an entire periphery, the second center position and the first center position being located at different positions around the metal seal. 
     
     
       2. The metal seal as set forth in  claim 1 , wherein the cantilever flexural rigidity compared only by cross-sectional configurations is increased gradually and/or slopingly from the first center position of the R-shaped curved portion to the second center position of the straight side portion, and the cantilever flexural rigidity is set larger on the second center position than on the first center position. 
     
     
       3. A metal seal, of which entire configuration is a closed non-circular ring having an R-shaped curved portion and a straight side portion to seal by contact with each of two facing flat faces, comprising a construction in which a cross-sectional configuration of a cantilever flexural rigidity of the metal seal is ununiform for an entire periphery as to make contact pressure of the metal seal against each of the two flat faces uniform for the entire periphery, wherein the cantilever flexural rigidity compared only by cross-sectional configurations is increased in at least one of gradual manner and sloping manner from the first center position of the R-shaped curved portion to the second center position of the straight side portion, the second center position and the first center position being located at different positions around the metal seal. 
     
     
       4. The metal seal as set forth in  claim 3 , wherein the cantilever flexural rigidity is set larger on the second center position than on the first center position.